Mictlan, Cross Breeding and Luck

Burden of Time isn't broken. It's just something that will force you to deal with it visibly instead of the invisible threat of giving an opponent a massive gem income (which is a common misconception).

Every Global Enchantment has an impact on the game if you allow it to remain unchecked. So having the ability to deal with, or counter them is something you must do even in SP. If you play the game without having the ability to deal with either letting the enchantment stick, or kicking it out/dispeling it, you are asking to be burnt.